The Lincoln Excalibur 7018 MR Low-Hydrogen Stick Electrode is a low-hydrogen iron-powder basic-coated moisture-resistant SMAW electrode classified to AWS A5.1/A5.1M E7018 H4R. It is engineered for code-quality fabrication on mild and low-alloy steels where diffusible hydrogen control, excellent puddle visibility, and superior out-of-position operability are required — making it a benchmark choice for power generation, petrochemical, and structural work. The H4R designation, combined with Lincoln Electric's proprietary moisture-resistant coating technology, delivers up to 60% less moisture pickup versus competitive E7018 electrodes, reducing the risk of hydrogen-induced cracking in demanding field and shop environments.
- Classification: AWS A5.1/A5.1M E7018 H4R
- Best for: All-position low-hydrogen welding on mild steel and low-alloy steel in structural, pressure vessel, and process piping applications
- Polarity: DC+ or AC
- Positions: All positions except vertical down
- Available diameters: 3/32 in, 1/8 in, 5/32 in, 3/16 in, 7/32 in, 1/4 in
- AWS Classification: AWS A5.1/A5.1M E7018 H4R
- Coating: Low-hydrogen iron-powder basic (lime-fluoride) coating with moisture-resistant H4R designation; formulated to resist moisture pickup up to 60% better than competitive E7018 electrodes
- Polarity: DC reverse polarity (DCEP/electrode positive) preferred for optimum arc stability; AC is also acceptable on machines with adequate open-circuit voltage; Lincoln publishes slightly higher AC amperage ranges than DC+ ranges
- Welding positions: All positions including vertical-up and overhead, except vertical down; larger diameters (3/16 in and above) recommended for flat and horizontal positions only
- Hydrogen designator: H4R (≤4 mL H₂/100 g deposited weld metal; moisture-resistant coating — 60% less moisture pickup vs. competition)
- Typical amperage: 70–110 A DC+ / 80–120 A AC (3/32 in); 90–160 A DC+ / 100–160 A AC (1/8 in); 130–210 A DC+ / 140–210 A AC (5/32 in); 180–300 A DC+ / 200–300 A AC (3/16 in); 250–330 A DC+ / 270–370 A AC (7/32 in); 300–400 A DC+ / 325–420 A AC (1/4 in)
- Charpy V-notch impact: 27 J (20 ft·lbf) min @ -29 °C (-20 °F) per AWS E7018 H4R; typical 121–332 J (89–246 ft·lbf) @ -29 °C (-20 °F)
- Available diameters: 3/32 in, 1/8 in, 5/32 in, 3/16 in, 7/32 in, 1/4 in
- Pack sizes: 8 lb Easy Open Can (3-Pack), 10 lb Easy Open Can (3-Pack), 50 lb Easy Open Can, 50 lb Easy Open Can (Buy America)
| Diameter | Pack size | Manufacturer part number |
|---|---|---|
| 3/32 in | 8 lb Easy Open Can (3-Pack) | ED033940 |
| 3/32 in | 10 lb Easy Open Can (3-Pack) | ED032588 |
| 3/32 in | 50 lb Easy Open Can | ED028280 |
| 3/32 in | 50 lb Easy Open Can (Buy America) | ED033868 |
| 1/8 in | 10 lb Easy Open Can (3-Pack) | ED032589 |
| 1/8 in | 10 lb Easy Open Can (3-Pack) | ED033838 |
| 1/8 in | 50 lb Easy Open Can (Buy America) | ED033869 |
| 1/8 in | 50 lb Easy Open Can | ED028281 |
| 5/32 in | 10 lb Easy Open Can (3-Pack) | ED033839 |
| 5/32 in | 10 lb Easy Open Can (3-Pack) | ED032590 |
| 5/32 in | 50 lb Easy Open Can | ED028282 |
| 5/32 in | 50 lb Easy Open Can | ED033870 |
| 3/16 in | 50 lb Easy Open Can | ED028283 |
| 3/16 in | 50 lb Easy Open Can (Buy America) | ED033871 |
| 7/32 in | 50 lb Easy Open Can | ED034307 |
| 7/32 in | 50 lb Easy Open Can | ED038367 |
| 1/4 in | 50 lb Easy Open Can | ED038368 |
Excalibur 7018 MR is purpose-built for code-driven all-position welding on mild and low-alloy steels:
- Structural steel fabrication and erection (AWS D1.1 code work)
- Pressure vessel fabrication and repair (ASME Section VIII)
- Power generation equipment and boiler components
- Pressure piping and pipefitting (ASME B31.1 / B31.3)
- Petrochemical plant construction and maintenance
- Shipbuilding and marine structural assemblies
- General mild steel fabrication requiring low-hydrogen deposits
- Store unopened cans in a clean, dry area; once opened, hold rods in a heated rod oven at 250–300°F until use to maintain H4R diffusible hydrogen levels.
- If electrodes have been exposed to atmosphere for more than a few hours after opening, recondition by baking at 500–550°F for 1 hour before use.
- Set the welding machine to DC+ (electrode positive) for best arc stability and weld quality; AC is acceptable on smaller machines — use the AC amperage range in that case.
- Select amperage within the published range for the diameter in use: 70–110 A DC+ for 3/32 in, 90–160 A DC+ for 1/8 in, 130–210 A DC+ for 5/32 in; for out-of-position work, dial to the lower one-third of the range.
- Strike the arc with a brief tap-and-drag; maintain a short arc length (approximately equal to the electrode diameter) to minimize hydrogen pickup and spatter.
- Use stringer beads or narrow weaves; limit weave width to 2–3× electrode diameter — the Excalibur 7018 MR's square coating burn-off and self-peeling slag facilitate clean multi-pass runs.
- Allow each pass to cool to interpass temperature (≤300°F unless the WPS specifies otherwise); remove slag completely between passes; return unused rods to the heated oven after welding.
Compared to standard E6013 (rutile, mild steel), E7018 delivers approximately 10 ksi higher tensile strength and far lower diffusible hydrogen — making it mandatory for crack-sensitive, code-governed work where E6013 is inadequate. Compared to E7018-1 H4R (the tougher sibling with Charpy requirement at -46°C vs. E7018's -29°C), the standard 7018 MR is the more economical choice for applications that do not require assured toughness at temperatures below -20°F. Stepping up to E8018-C3 or E9018-M adds low-alloy or Ni-Mo alloying for higher tensile strength and better low-temperature toughness on alloy steels, but neither is needed for mild steel work where Excalibur 7018 MR provides the optimal balance of performance, operability, and value.
What is the AWS classification of Lincoln Excalibur 7018 MR?
The Excalibur 7018 MR is classified AWS A5.1/A5.1M E7018 H4R — a mild steel, low-hydrogen iron-powder electrode with a moisture-resistant coating that limits diffusible hydrogen to ≤4 mL per 100 g of deposited weld metal.
Can Excalibur 7018 MR run on AC or DC?
Yes — it runs on both DC+ (electrode positive) and AC. DC+ is preferred for the smoothest arc and best mechanical properties. On AC, use the slightly higher amperage ranges published by Lincoln (e.g., 80–120 A AC vs. 70–110 A DC+ for 3/32 in diameter).
What does the MR (Moisture Resistant) designation mean?
MR indicates the coating is specially formulated to resist moisture reabsorption from the atmosphere. Lincoln Electric's Excalibur 7018 MR picks up 60% less moisture than competitive E7018 electrodes, reducing the risk of hydrogen-induced cold cracking — especially important in humid or outdoor environments.
Do I need to bake or recondition these electrodes before use?
Unopened cans do not require baking if stored properly in a dry location. Once opened, hold rods in a heated rod oven at 250–300°F. If rods have been out of the oven for an extended period, recondition at 500–550°F for 1 hour to restore H4R hydrogen levels before use.
What positions can I weld in with Excalibur 7018 MR?
All positions except vertical down — including flat, horizontal, vertical-up, and overhead. For out-of-position work, set amperage to the lower portion of the published range for the diameter. Note that the larger diameters (3/16 in and above) are best suited for flat and horizontal positions only.
Shop Lincoln Excalibur 7018 MR Low-Hydrogen Stick Electrode at WeldingMart.com — competitive pricing, fast shipping, and the largest in-stock selection of Lincoln Electric SMAW consumables. Backed by Lincoln Electric's Q2 Lot® quality system — with actual deposit chemistry and mechanical test results available online — and the Excalibur brand's decades of proven performance as the industry's benchmark low-hydrogen stick electrode for structural, pressure vessel, and process piping applications.